Field of the Invention
Embodiments of the present invention generally relate to containers and methods for the collection, transportation and analysis of fluid samples.
Description of the Related Art
Having the ability to collect, differentiate and categorize different gas mixtures and their individual components has long been a necessity for the purposes of energy exploration and source identification of stray gases (i.e., differentiating gases from landfills, gas storage fields, producing wells, etc.). However, in order to do so successfully, one often needs to obtain samples from different potential source gases, and then submit the samples for detailed testing and comparison. Because analysis of the chemical composition can often be inconclusive in differentiating similar gases, isotope analysis of individual components of the gas can often provide an effective means of distinguishing two otherwise chemically identical gas sources. For instance, methane from a sanitary landfill is isotopically different from methane associated with petroleum. Similarly, isotope analysis of certain gas components can also provide insight to the mechanism of formation of the gases, and therefore give insight into the commercial viability of the gas source. Unfortunately, the transfer and shipment of hazardous materials (e.g., flammable and/or toxic gases) is often costly and usually requires specialized training. In some instances, air shipment of such gases is strictly forbidden (i.e. toxic gases). One such component of interest often associated with natural gas is hydrogen sulfide (H2S).
Typical ways of collecting gases containing hydrogen sulfide (H2S) have included the use of containers like gas bags, chemically treated metal cylinders, and glass vials. Such containers are often fragile, expensive and unwieldy. In some instances, samples containing toxic concentrations of H2S are strictly forbidden on aircraft. In parts of the world where isotope analysis is not available, the only means of transporting such samples to a laboratory with isotope analysis capability would be via ocean freight, and then via ground transport. This procedure often consumes valuable time and resources, as the shipping of hazardous materials involves specialized training for the shipper as well as associated hazardous shipping fees and restrictions. H2S is also highly reactive and may react with the vessel in which it is contained. For instance, untreated stainless steel cylinders can completely “remove” H2S from a gas mixture.
Once in the lab, the current technology for extracting sulfur from H2S for isotopic analysis is to flow the gas through various solutions. The current solutions include cadmium acetate, silver phosphate, zinc acetate, and silver phosphate/silver nitrate solutions. All of these methods utilize liquid solutions and except for zinc acetate are hazardous.
Therefore, there is a need for improved containers and methods for the collection, transportation, and analysis of fluid samples.